我有一个奇怪的错误，列表和解析，我无法弄清楚。每当我尝试在解析请求中查询和find()时，我有时会收到java.lang.String cannot be cast to org.json.JSONObject错误。
当我到达我的代码的这一部分时会发生这种情况：
private List<ParseUser> users;
......
else if (viewStatus == 2) {
Log.d("Friends view", "getting current user");
ParseUser current = ParseUser.getCurrentUser();
Log.d("Friends view", "Getting friend relation of user");
ParseRelation <ParseUser> friendRelation = current.getRelation("friends");
Log.d("Friends view", "Getting relation query");
ParseQuery <ParseUser> queryFriends = friendRelation.getQuery();
Log.d("Friends view", "Getting friend query");
try {
users = queryFriends.find();
} catch (ParseException e) {
Log.e("queryUsers", "error: " + e);
}
Log.d("Friends view", "users = query done");
}
最奇怪的部分是，一旦我让用户在第一次注销后重新登录，我再也没有遇到过这个问题。这与ParseUser.getCurrentUser();有关吗？
错误：
07-09 20:11:35.723 17089-17089/com.curtain.projectcurtain D/List Click﹕ Position = 3
07-09 20:11:36.543 980-980/? I/SBar.NetworkController﹕ onDataActivity: direction=3
07-09 20:11:36.553 980-980/? I/SBar.NetworkController﹕ refreshSignalCluster: mobile: mHasMobileDataFeature=true DataTypeShown=zz_moto_stat_sys_data_fully_connected_4g_lte_waves_wide Activity=zz_moto_stat_sys_data_fully_inandout_waves_animation_wide in=false out=false Accessibility="4 G L T E"
07-09 20:11:38.225 17089-17241/com.curtain.projectcurtain D/Friends view﹕ getting current user
07-09 20:11:38.226 17089-17241/com.curtain.projectcurtain D/Friends view﹕ Getting friend relation of user
07-09 20:11:38.226 17089-17241/com.curtain.projectcurtain D/Friends view﹕ Getting relation query
07-09 20:11:38.226 17089-17241/com.curtain.projectcurtain D/Friends view﹕ Getting friend query
07-09 20:11:38.229 17089-17241/com.curtain.projectcurtain W/dalvikvm﹕ threadid=14: thread exiting with uncaught exception (group=0x4170dd40)
07-09 20:11:39.273 236-509/? I/SFPerfTracer﹕ triggers: (rate: 0:46) (3805837 sw vsyncs) (0 skipped) (534:1361110 vsyncs) (536:5190383)
07-09 20:11:40.557 980-980/? I/SBar.NetworkController﹕ onDataActivity: direction=0
07-09 20:11:40.564 980-980/? I/SBar.NetworkController﹕ refreshSignalCluster: mobile: Signal=zz_moto_stat_sys_signal_5bar_2_fully_wide Roaming=(none) mSimIconId=(none) Accessibility="Phone two bars.","Not roaming.",""
07-09 20:11:40.564 980-980/? I/SBar.NetworkController﹕ refreshSignalCluster: mobile: mHasMobileDataFeature=true DataTypeShown=zz_moto_stat_sys_data_fully_connected_4g_lte_waves_wide Activity=zz_moto_stat_sys_data_fully_connected_waves_none_wide in=false out=false Accessibility="4 G L T E"
07-09 20:11:41.320 17089-17241/com.curtain.projectcurtain E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #2
Process: com.curtain.projectcurtain, PID: 17089
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:300)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
Caused by: java.lang.ClassCastException: java.lang.String cannot be cast to org.json.JSONObject
at com.parse.ParseRESTQueryCommand.constructParameters(ParseRESTQueryCommand.java:84)
at com.parse.ParseRESTQueryCommand.findCommand(ParseRESTQueryCommand.java:15)
at com.parse.NetworkQueryController.findAsync(NetworkQueryController.java:49)
at com.parse.NetworkQueryController.findAsync(NetworkQueryController.java:27)
at com.parse.OfflineQueryController.findAsync(OfflineQueryController.java:26)
at com.parse.ParseQuery.findAsync(ParseQuery.java:1184)
at com.parse.ParseQuery$3$1.then(ParseQuery.java:1176)
at com.parse.ParseQuery$3$1.then(ParseQuery.java:1172)
at bolts.Task$14.run(Task.java:796)
at bolts.BoltsExecutors$ImmediateExecutor.execute(BoltsExecutors.java:105)
at bolts.Task.completeAfterTask(Task.java:787)
at bolts.Task.continueWithTask(Task.java:599)
at bolts.Task.continueWithTask(Task.java:610)
at bolts.Task$12.then(Task.java:702)
at bolts.Task$12.then(Task.java:690)
at bolts.Task$14.run(Task.java:796)
at bolts.BoltsExecutors$ImmediateExecutor.execute(BoltsExecutors.java:105)
at bolts.Task.completeAfterTask(Task.java:787)
at bolts.Task.continueWithTask(Task.java:599)
at bolts.Task.continueWithTask(Task.java:574)
at bolts.Task.onSuccessTask(Task.java:690)
at bolts.Task.onSuccessTask(Task.java:680)
at bolts.Task.onSuccessTask(Task.java:714)
at com.parse.ParseQuery$3.call(ParseQuery.java:1172)
at com.parse.ParseQuery$3.call(ParseQuery.java:1169)
at com.parse.ParseQuery.doWithRunningCheck(ParseQuery.java:1108)
at com.parse.ParseQuery.findAsync(ParseQuery.java:1169)
at com.parse.ParseQuery.findInBackground(ParseQuery.java:1137)
at com.parse.ParseQuery.find(ParseQuery.java:957)
at com.curtain.projectcurtain.AddFriends$RemoteDataTask.doInBackground(AddFriends.java:106)
at com.curtain.projectcurtain.AddFriends$RemoteDataTask.doInBackground(AddFriends.java:55)
at android.os.AsyncTask$2.call(AsyncTask.java:288)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
07-09 20:11:41.332 855-1233/? W/ActivityManager﹕ Force finishing activity com.curtain.projectcurtain/.AddFriends
AddFriends.java：
public class AddFriends extends ListActivity {
//Global variables
public static final int ADD_ID = Menu.FIRST;
public static final int REQUESTS_ID = Menu.FIRST + 1;
public static final int FRIENDS_ID = Menu.FIRST + 2;
public static final int DELETE_ID = Menu.FIRST + 3;
public TextView title;
public static int viewStatus = 0;
private List<ParseUser> users;
private List<ParseObject> requests;
Button btnAdd, btnRequests, btnFriends;
//Grabbing users and putting them in the list
private class RemoteDataTask extends AsyncTask<Void, Void, Void> {
protected Void doInBackground(Void... params) {
if (users != null){
users = null;
}
//add friends view
if (viewStatus == 0 ) {
ParseQuery<ParseUser> queryUsers = new ParseQuery<ParseUser>("_User");
queryUsers.orderByDescending("createdAt");
queryUsers.whereNotEqualTo("username", ParseUser.getCurrentUser().getUsername());
try {
users = queryUsers.find();
} catch (ParseException e) {
Log.e("queryUsers", "error: " + e);
}
}
//show requests
else if (viewStatus == 1) {
//grab requests only
ParseQuery<ParseObject> queryRequests = new ParseQuery<ParseObject>("FriendRequests");
queryRequests.whereEqualTo("to", ParseUser.getCurrentUser());
queryRequests.whereEqualTo("status", "waiting");
try {
requests = queryRequests.find();
} catch (ParseException e) {
Log.e("queryUsers", "error: " + e);
}
}
//View friends
else if (viewStatus == 2) {
Log.d("Friends view", "getting current user");
ParseUser current = ParseUser.getCurrentUser();
Log.d("Friends view", "Getting friend relation of user");
ParseRelation <ParseUser> friendRelation = current.getRelation("friends");
Log.d("Friends view", "Getting relation query");
ParseQuery <ParseUser> queryFriends = friendRelation.getQuery();
Log.d("Friends view", "Getting friend query");
try {
users = queryFriends.find();
} catch (ParseException e) {
Log.e("queryUsers", "error: " + e);
}
Log.d("Friends view", "users = query done");
}
return null;
}
//before execution
@Override
protected void onPreExecute() {
super.onPreExecute();
}
//while executing
@Override
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
}
@Override
protected void onPostExecute(Void result) {
//puts users into list view
ArrayAdapter<String> adapter = new ArrayAdapter<String> (AddFriends.this, R.layout.friends_row);
if (users != null && viewStatus != 1) {
for (ParseUser user : users){
adapter.add((String) user.get("username"));
}
}
//because requests come in as a parseObject instead of a ParseUser
else if (viewStatus == 1 && requests != null){
for (ParseObject request : requests){
adapter.add(request.getParseUser("from").getUsername());
}
}
Log.d("View", "Done, setting list adapter..");
setListAdapter(adapter);
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_friends);
title = (TextView) findViewById(R.id.friendsTitle);
title.setText("Send a friend request to one of the following:");
new RemoteDataTask().execute();
registerForContextMenu(getListView());
//Add a friend
btnAdd = (Button) findViewById(R.id.button);
btnAdd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
title.setText("Send a friend request to one of the following:");
viewStatus = 0;
new RemoteDataTask().execute();
registerForContextMenu(getListView());
}
});
//View friend requests button
btnRequests = (Button) findViewById(R.id.button2);
btnRequests.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
title.setText("Tap to accept request, hold to deny");
viewStatus = 1;
new RemoteDataTask().execute();
registerForContextMenu(getListView());
}
});
//Friends button
btnFriends = (Button) findViewById(R.id.button3);
btnFriends.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
title.setText("Your friends. Hold to delete them");
viewStatus = 2;
new RemoteDataTask().execute();
registerForContextMenu(getListView());
}
});
}
.....
注意：这是开发的早期阶段。现在主要只是编程功能。想尽早弄清楚这个错误。非常感谢任何帮助/建议。
提前致谢！